1. Field of the Invention
The invention relates generally to building foundations and more specifically to modular foundations.
2. Background
Typical building foundations are constructed either as complete or partially monolithic, cast-in-place structural elements. Due to the continuity requirements for both adequate structural response and to meet code requirements, construction of foundations is typically accomplished with as few joints within the foundation as possible. Such construction requires a significant amount of in-field manual labor to construct intricate rebar cages and mount the rebar cages on dobe blocks to ensure minimum concrete cover and correct location of rebar within the cast-in-place concrete foundation. During the pouring of the concrete and the vibration of the concrete during and after the pour, the rebar cages can become dislodged and rebar may, after the pour and vibration, be accurately placed within the foundation. Additional site-pour problems include concrete quality issues, air entrainment problems, section adhesion problems and improper vibration leading to excess settling.
Additionally, conventional systems and methods are generally designed almost exclusively for use with gravel ballast footers. Moreover, an inherent weakness of conventional site-pour foundations is that the quantity of steel reinforcement that can be used is limited by patterns/structural design.
What is needed is a modular foundation system that offers simple field assembly of the modules, accurate alignment of foundation modules and accurate placement of rebar within the shop-fabricated modules.